3.1 Can mobile phone use increase the risk of brain tumours?

Whether the use of mobile phones is associated with an
increased risk of brain
tumours has been the
research question of numerous small and a handful of large-scale
epidemiological
studies. Attention has focused on the possibility of
tumours of the head and neck region because these tissues are
primarily exposed to the RF fields emitted by hand-sets.
Furthermore, some studies suggested a possible association
between the exposure to RF EMF produced by mobile phones and an
increased risk of cancer of
the auditory acoustic nerve
(acoustic neuroma) and
brain tumours (glioma).

However, the results of cohort and incidence time trend
studies do not support an increased risk for glioma. The
possibility of an association with
acoustic neuroma
remains open. In particular, the observed rate of glioma
incidence in the Nordic countries has been compared to the
predicted rates that would have been observed if there were an
increased risk of 1.2, 1.5 and 2 related to a regular mobile
phone use of 10 years or more. The observed
cancer incidence does
not show the predicted steep increase that would be expected if
there were a causal link between mobile phones and
cancer.

The fact that the rates of incidence of the corresponding
tumours have not
increased since the introduction of cell phones suggests thus
precaution on the interpretation of such a hypothetical
association.

3.1.1 What about an increased risk of cancer for children?

The only epidemiological
study on mobile phone use and brain
tumours in children
which involved four European countries did not show an increased
risk. However, more studies are needed.

3.1.2 What about an increased risk of other cancer types?

Epidemiological studies
do not indicate increased risk for other
malignant diseases
including childhood cancer.
A number of studies also looked into the potential
cancer risk of
exposure to radio frequency fields from transmission towers. In
most cases, no conclusions on a cancer risk could be
drawn.

3.2 Have experimental studies revealed an increased cancer risk?

A considerable number of well-performed in vivo studies using a wide variety of animal models have been
mostly negative in outcome. Among these, a number of lifetime
and long-term RF fields exposure studies were performed on
laboratory animals by exposing them to 900 MHz GSM signals and
other higher frequency signals at higher exposure levels than in
earlier studies. All studies concluded that there was no effect
of RF fields on the risk of developing
tumours, even at the
higher exposures. One study found a reduced survival rate in
exposed animals, but this finding remains unexplained.

The results of the new experimental studies are consistent
with results from previous studies and, overall, add to the
evidence that the RF fields such as those emitted by mobile
phones do not cause cancer
in laboratory animals.

3.3 Have studies on cell cultures revealed genetic effects?

An analysis of 88 in vivo and in vitro studies published between 1990 and 2011 and assessing
genetic damage in human cells exposed to RF showed that the
magnitude of difference between RF- exposed and sham-exposed
controls was small with some exceptions. Globally, these studies
did not provide evidence for any effect of radio frequency field
on the genetic material of
cells.

Other potential effects were also investigated, such as cell
death, expression of genes, of cell proliferation. Most of the
studies did not find any effect.